Sinking Atlantic Coastline Meets Rapidly Rising Seas

My Comments: Our esteemed Governor, Rick Scott, has decreed that the phrase ‘climate change’ cannot be uttered by any state employee. OK.

But it doesn’t change the reality that the planet is experiencing a warming trend that may or may not be influenced by advances in human activity. The reality is that for the foreseeable future, our coastlines, and those who live there, are going to be increasingly under threat. I happen to live in central Florida where coastal flooding last happened many millions of years ago and I suspect I’ll be long gone before it happens again.

But my grandchildren will experience over the next 70 years and more what some of us can rationally predict will happen. Some effort by our elected leaders, to mitigate the threat, seems to be a rational expectation.

By John Upton, Climate Central on April 14, 2016

The 5,000 North Carolinians who call Hyde County home live in a region several hundred miles long where coastal residents are coping with severe changes that few other Americans have yet to endure.

Geological changes along the East Coast are causing land to sink along the seaboard. That’s exacerbating the flood-inducing effects of sea level rise, which has been occurring faster in the western Atlantic Ocean than elsewhere in recent years.

New research using GPS and prehistoric data has shown that nearly the entire coast is affected, from Massachusetts to Florida and parts of Maine.

The study, published this month in Geophysical Research Letters, outlines a hot spot from Delaware and Maryland into northern North Carolina where the effects of groundwater pumping are compounding the sinking effects of natural processes. Problems associated with sea level rise in that hot spot have been — in some places — three times as severe as elsewhere.

“The citizens of Hyde County have dealt with flooding issues since the incorporation of Hyde County in 1712,” said Kris Noble, the county’s planning and economic development director. “It’s just one of the things we deal with.”

On average, climate change is causing seas to rise globally by more than an inch per decade. That rate is increasing as rising levels of greenhouse gases in the atmosphere trap more heat, melting ice and expanding ocean waters. Seas are projected to rise by several feet this century — perhaps twice that much if the collapse of parts of the Antarctic ice sheet worsens.

Ocean circulation changes linked to global warming and other factors have been causing seas to rise much faster than that along the sinking mid-Atlantic coastline — more than 3.5 inches per decade from 2002 to 2014 north of Cape Hatteras in North Carolina, a recent study showed.

The relatively fast rate of rise in sea levels along the East Coast may have been a blip — for now. The rate of rise recorded so far this century may become the norm during the decades ahead. “Undoubtedly, these are the rates we’re heading towards,” said Simon Engelhart, a University of Rhode Island geoscientist.

Engelhart drew on data from prehistoric studies and worked with two University of South Florida, Tampa scientists to combine it with more modern GPS data to pinpoint the rates at which parts of the Eastern seaboard have been sinking.

Their study revealed that Hyde County — a sprawling but sparsely populated farming and wilderness municipality north of the Pamlico River — is among the region’s fastest-sinking areas, subsiding at a little more than an inch per decade.